1. 1 Department of Pharmacy, Faculty of Science, National University of Singapore, 18 Science Drive 4, 117543Singapore
2. 2 Department of Pharmacy, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng 308433, Singapore
3. 3 Communicable Disease Center, Institute of Infectious Diseases and Epidemiology, Department of Infectious Disease, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng 308433, Singapore
4. 4 Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road 119228, Singapore